摘要
三维构造恢复不仅可以验证构造解释在三维空间的一致性,也可用于计算构造内部的应变状态,确定构造位移变化路径及地层力学结构对构造生长过程的影响。在Gocad三维平台上综合遥感、地震和钻井等资料,建立准噶尔盆地南缘主要勘探目的层古近系古新统—始新统紫泥泉子组(E1-2z)的面模型和霍尔果斯深层背斜的体模型,并在体模型的三维域中设置剪切模量、拉梅常数以及岩层密度,以求真实反映实际地层力学结构。在此基础上利用基于Gocad平台开发的三维构造恢复插件对两者开展恢复试验。面模型恢复结果表明,准噶尔盆地南缘山前逆冲断层上盘的恢复应变椭球长轴多呈北西方向,与该位置天山山体和山前断裂带走向斜交,这一特征印证了晚新生代以来的斜向挤压作用。但在山前第二排背斜带东西300km的范围内,恢复应变椭球长轴由霍尔果斯背斜处的近南北逐渐向东西两侧的北北东向和北西向过渡,揭示出深部隐伏断裂可能具有前陆地区典型的弧形冲断特征。体模型恢复结果表明,霍尔果斯深层背斜内部的应变状态与其所经历的运动学过程并没有显著的对应关系,恢复应变分布主要受相邻地层之间力学结构的差异控制,这就导致同一断块不同地层内部的应变状态具有不同的分布特征。在石油勘探开发领域,针对圈闭范围小尺度构造的恢复应变计算可用于构造裂缝性质、方位和分布的预测。
Three-dimensional （3-D） restoration may help to validate volumetric consistency of structural interpretations; moreover,it is increasingly used as a means to address effects of mechanical properties in structural growth,and to estimate strain distribution within structures. We have constructed the tsurfs model of the Paleocene-Eocene Ziniquanzi Formation and the solid model of Huoerguosi deep anticline in the Southern Junggar Basin based on the interpretation of depth converted,two-and three-dimensional seismic data,with stratigraphic horizons by well control and surface geology defined by remote sensing data. In order to truly represent mechanical properties of rock units,shear module,Lame＇s constants and density were specified in the three-dimensional regions of the solid model. Then,we used a combination of horizon-based and volumetric restoration techniques,implemented in Gocad＇s structural restoration plug-in unit,to restore these two types of models. The axes of maximum principal strain,derived from the restoration of tsurfs model of Paleocene-Eocene Ziniquanzi formation in hanging wall of mountain front thrust faults,mostly extend north-west direction,which are obliquely intersecting with the Tianshan and the mountain front thrust belts. This characteristic may verify the oblique contraction in the Southern Junggar Basin since the Late Cenozoic. Moreover,in the three anticlinal belts extending east-west over 300 km2 area,the axes of maximum principal strain change from south-north in Huoerguosi anticline to north-east eastward and north-west westward,which indicates the arc shaped thrusting,the typical thrusting style in foreland area and in deep structures. The strain distribution derived from the restoration of Huoerguosi deep anticline solid model do not have obviously corresponding relationship to the kinematic process,but are mainly controlled by contrasts in the mechanical strength of rock units,which caused the varieties of strain distributions in the same fault block. In the petroleum exploration and development,this volumetric restoration technique can be used as a means to estimate strain distributions within structural traps,which may help to predict patterns of natural fracture or other small scale structures.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2010年第4期140-150,共11页
Earth Science Frontiers
基金
国家科技重大专项课题(2008ZX05003-001)
国家重点基础研究发展计划"973"项目01课题(2006CB202301)
国家自然科学青年基金项目(40802047)
关键词
三维构造恢复
面模型
体模型
力学模型
恢复应变
Gocad平台
volumetric structural restoration
tsurfs model
solid model
mechanical property
restoration strain
Gocad modeling system
